Bis [2-(1-methoxysopropoxyisopropoxy) ethyl] ether



BIS[2-(l-METHOXYISOPROPOXYISOPROPOXY) ETHYL] ETHER Thomas F. Banigan, Jr., Walnut Creek, Calif., assignor to Tidewater Oil Company, a corporation of Delaware No Drawing. pplication April 19, 195

Serial No. 579,171

2 Claims. (Cl. 260-615) This invention relates to a new composition of matter,

namely, bis[2-(1-methoxyisopropoxyisopropoxy) ethyl] ether, and to a method for its preparation.

One object of the invention is to provide a new compound having utility as a fuel additive.

Another object of the invention is to provide a method for manufacturing bis[2-(1-methoxyisopropoxyisopropoxy) ethyllether.

Another object of the invention is to provide a gasoline additive that gives a cleaner fuel for internal combustion engines, such as automobile engines. Progress in the automobile industry has resulted in the development of gasoline engines of increasingly higher compression pressures, requiring gasoline fuels with correspondingly higher anti-knock properties or octane rating. Modern refiners in an effort to obtain adequate yields of high octane gasoline are resorting to the newer processes of catalytic cracking, catalytic reforming and polymerization, and delayed or fluid coking. The stocks from such processes can provide the desired octane rating, but unfortunately such stocks often contain unstable components which tend to form deposits in critical parts of the induction system such as the carburetor throat, intake manifold and intake valve ports. Heretofore, use of gasolines made from these stocks has commonly resulted in fouling such parts in a few thousand miles, especially where the cars have been subjected to city driving or other lowoutput types of use. As these deposits accumulate, the engines idling becomes labored and uneven, and stalling often results. Deposits also form in the combustion chamber, and, as a result of the various deposits, the engine exhibits a loss of power, gives poor gasoline mileage, and eventually requires higher octane fuel.

These conditions are the result of unstable constituents in the fuel reacting under the influence of heat, oxygen, blowby gases and exhaust gases. While it might be possible to refine all unstable constituents out of the fuel, it is generally not feasible to do so, The deposit-forming tendency at times is accentuated when lead tctraethyl and dyes are present. I

Many substances have been tried as gasoline additives in attempts to solve the above problems, but the results have fallen far short of expectations. Various detergents and gum solvents have been mixed with the gasoline in an attempt to prevent the formation of deposits. Many volatile polar compounds which should be capable of dissolving the deposits have been tried, unsuccessfully. Acetone and other ketones, tetrahydrofuran, oxydipropionitrile, iminodipropionitrile, morpholine, quinoline, cyclohexanone, nitrobenzene, di-tertiarybutyl-paracresol, polypropylene glycols and ammonium mahogany sulfonate are among the compounds tried. None of these appear to give improvement in overall engine cleanliness; some of them decrease deposits in one part of the engine only to transfer what they pick up to other parts of the engine, where they are redeposited. Some of these contribute to the deposits in the carburetor and on the valve Patented Sept. 23, 1958 stems; some cause ring sticking; and some increase overall dirtiness throughout the engine.

Other types of gasoline additives, such as tricresyl phosphate, do not reduce the engine deposits but rely instead on chemical change of the deposits in the combustion chamber to suppress preignition usually resulting from such deposits. This type of additive is of no value in preventing induction system deposits or piston-ring stick- Other objects and advantages of the invention will appear from the following description.

Bis [2 (1 methoxyisopropoxyisopropoxy) ethyllether has the formula It is prepared from the following reagents in substantially the following proportions:

Reagents Proportions Moles by Weight Methoxydipropylene glyc0l 800 5. 4 2-Chloroethyl ether (Ohlorex" 286 2. 0 Sodium metal I 92 Y .4. 0

The sodium is preferably added to the glycol in small chunks while stirring the glycol, which is preferably kept at a temperature of about 140 C. The addition is preferably done at a speed assuring a smooth exothermic reaction, the result of which is a viscous, light-yellow sod um alcoholate of the following formula:

CH3- (0C2H3CH3 2ONa resulting from the reaction:

The mixture may then be cooled, filtered to remove the sodium chloride, and the filter cake washed with pentane. The pentane washings are combined with the main filtrate which is then extracted with calcium chloride solution to remove any excess of the glycol ether. Inpreparation of this substance, yields of between 60% and of theoretical may be expected. The reaction product is then purified by fractional distillation through a multiplate fractionation column.

The distilled polyether is a colorless, slightly viscous liquid. It is completely miscible with organic solvents such as benzene, xylene, pentane, octane, iso-octane, ethyl alcohol and ethyl ether, but only partially soluble in water. The compound is stable, as shown by the fact that one sample stored for eight months, in a clear bottle, showed no change in'color or properties. The compound is inflammable, burning readily with no smoke and essentially no carbon residue.

Analysis of a heart-cut from the fractionation gave the empirical formula C13H38O7. There was no chlorine present, showing that the reaction had gone to completion. This heart-cut exhibited the following physical properties:

Boiling point, C.:

At 770 mm. (atmos. press.) 185 At 30 mm i 107 Freezing point, C glass below 60 Refractive index, n 1.4214 Density, d 0.9527 Molecular refraction:

Experimental (Lorentz & Lorenz) 97.5

Theoretical (Auwers & Eisenlohr) 96.8 Viscosity:

Saybolt seconds 100 F 34.3

Centistokes 100 F 2.46 Carbon residue, percent less than 0.01 Solubility in water 25 C., g./100 g 12 Performance tests have shown that the present invention produces substantial improvement in engine cleanliness, as compared to the same fuel not containing the additive. The test procedure (designated hereinafter as 40-E procedure) involves a 40 hour engine run on a dynamometer under conditions chosen to correlate, on an accelerated scale, with field performance. In this test a 216.5 cubic-inch, six-cylinder Chevrolet engine is run continuously for forty hours at a speed of 1900 R. P. M. (plus or minus 25 R. P. M.) under an engine load of 36 B. H. P. (plus or minus 1 B. H. P.). The jacket coolant inlet temperaturs is kept at 155 F. minimum, the jacket coolant outlet temperature is kept within two degrees of 170 F., and the crankcase oil temperature is kept within two degrees of 190 F. The air-fuel ratio is 14.5 (plus or minus 0.5) to l. The spark advance is 35 (plus or minus 3). The spark plug gap, ignition cam angle, valve clearance, exhaust back pressure and other similar conditions are also maintained at predetermined values. Before the test, the engine is disassembled and cleaned, and a new set of piston rings is installed. The engine is given a standard two-hour break-in before the actual test is begun.

After the test run of 40 hours, the engine is dismantled and inspected, and is rated on ten items, as follows:

(1) Piston skirt varnish rating.

(2) Cylinder wall varnish rating.

(3) Intake valve stem deposit rating.

(4) lntake valve tulip deposit rating.

("5) Intake port deposit rating.

(6) Overall engine sludge rating.

(7) Overall engine varnish rating.

On these first seven items, the rating runs between 0 for dirty to for clean.

(8) Corrosion or rust rating (10 for none, 9 for light, 8 for medium, and 7 for heavy corrosion).

(9) Stuck ring rating (10, minus 0.5 demerit for each 90 of ring stuck in the groove).

(10) Tight ring rating (10, minus 0.5 demerit for each tight ring). I

A perfectly clean engine will thus rate 100. A total rating of 85 is considered acceptable if the piston skirt varnish is 7.5 or better.

The gasoline employed in the tests discussed hereinafter for illustration was composed of about 50% mixed thermal naphtha having about 95-400 F. boiling range, about light straight-run naphtha having 95 250 F. boiling range, about heavy cracked (catalytic) naphtha having 270-400 F. boiling range, and about 5% .of light natural gasoline. It contained as additives about 1.75 ml. per gallon of tetraethyllead and an amine inhibitor in normal amounts. It analyzed 0.11% sulfur. Gum was present at about 2 to 5 mg. per 100 ml. in the ASTM test and the copper dish test showed about 16-26 mg. of gum per 100 ml. The gasoline had the following volatility specifications: 10% evaporated at 134-150 F., 50% at 244-250 F., and at about 360 F. The approximate composition of the gasoline was:

Percent Paraffins and naphthalenes about 66 Olefins do 16 Aromatics d0 18 Sulfur d0 0.1 Phenols do 0.4 Nitrogen do 0.001

Table I shows the results of such tests where 0.75 cc./ gal. of the new compound of this invention was used, in comparison with the same gasoline Without the bis- [2-( 1-methoxyisopropoxyisopropoxy ethyl] ether.

As blended into the gasoline, the new compound contained about 2% by weight of an antioxidant (phenylalphanaphthylamine) which had been added to assure against possible oxidation in storage and blending operations.

Table I Gasoline Control Plus Addi- Gasoline tive 75 gm./ gal.

Overall Rating 83 86. 5

Table II shows a breakdown of some of the items in the same test as Table I.

Table II Control Gasoline Gasoline plus Additive Piston skirt rating, 7. 5 8. 0 Intake valve tulip rating" 9.0 9.0 Intake valve stem rating 9. 0 9. 0 Stuck ring rating .1 8.0 10.0 Overall varnish 7. O 8. 0 Side pan sludge 7.0 8.0

The superior stuck-ring-rating of the gasoline containing the new additive is particularly impressive.

I claim:

1. Bis [2- 1-methoxyisopropoxyisopropoxy) ethyl] ether, having the formula References Cited in the file of this patent UNITED STATES PATENTS 2,089,580 Schulze Aug. 10, 1937 2,184,956 Gilliland et al Dec. 26, 1939 2,480,185 Fife et al Aug. 30, 1949 2,510,540 Ballard et a1 June 6, 1950 2,527,970 Sokol Oct. 31, 1950 2,662,859 Kirkpatrick Dec. 15, 1953 

1. BIS(2-(1-METHOXYISOPROPOXYISOPROPOXY) ETHYL)ETHER, HAVING THE FORMULA 